The present invention relates to an automatic vessel position holding control method and an automatic vessel position holding controller and more particularly to an automatic vessel position holding control method, a wave drifting force estimating method, an automatic vessel position holding controller and a dynamic positioning system which can drastically reduce deviations of a vessel position by performing feedforward control that estimates at least one of a wave drifting force and a wave drifting moment caused by waves and compensates for at least one of the estimated wave driving force and wave drifting moment or by performing feedforward control which estimates a long-period varying force that includes a varying wave drifting force by waves and compensates for the estimated long-period varying force.